Parents and children from ‘The Air Team’, an air pollution campaign group, celebrate the arrival of London’s Ultra Low Emission Zone (ULEZ), on 8th of April 2019 in London, Unted Kingdom. The new zone is one of the most ambitious clean air schemes in the world, and is expected to reduce road transport emissions by around 45%. An arch was set up with plant pots to be handed out to passersby and commuters were encouraged to walk through the arch.